US9081192B2ActiveUtilityA1
Optical scanning device, and image forming apparatus
Est. expiryNov 20, 2032(~6.3 yrs left)· nominal 20-yr term from priority
Inventors:Yoshiyuki Suzuki
G02B 26/127
45
PatentIndex Score
0
Cited by
12
References
5
Claims
Abstract
An optical scanning device includes a light source, a scanning portion that includes plural reflection surfaces, makes light beams incident to the reflection surface such that optical axis directions of the light beams emitted from the light emitting parts are tilted with respect to a direction perpendicular to the reflection surface, and scans the light beams in the main scanning direction through rotation, an optical system that includes an optical member made of a resin, is disposed between the scanning portion and the surface to be scanned, and makes the plural light beams incident to the surface to be scanned such that optical axes of the plural light beams are parallel to each other, and a correction portion that is provided in the optical system, and corrects positional deviation of scanning lines of the light beams in the sub-scanning direction on the surface to be scanned.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. An optical scanning device comprising:
a light source that includes a string of a plurality of light emitting parts provided with a gap in a main scanning direction of a surface to be scanned, is disposed in plurality in a sub-scanning direction and emits light beams;
a light source amount correction unit that corrects an amount of light emitted by the light source based on a portion of detected light;
a scanning portion that includes a plurality of reflection surfaces arranged in a circumferential direction with respect to a rotation axis, makes the light beams incident to the reflection surface such that optical axis directions of the light beams emitted from the plurality of light emitting parts are tilted with respect to a direction perpendicular to the reflection surface, and scans the light beams in the main scanning direction through rotation;
an optical system that includes an optical member made of a resin, is disposed between the scanning portion and the surface to be scanned, and makes the plurality of light beams incident to the surface to be scanned such that optical axes of the plurality of light beams are parallel to each other; and
a correction portion that is provided in the optical system, and corrects positional deviation of scanning lines of the light beams in the sub-scanning direction on the surface to be scanned,
wherein the optical system includes the optical member made of a resin in plurality,
wherein, in the correction portion, at least three surfaces of entrance surfaces and exit surfaces of the plurality of optical members have curvatures in the sub-scanning direction at positions of the optical axes in the main scanning direction which are different from curvatures in the sub-scanning direction at positions distant from the optical axes in the main scanning direction, and
wherein a curvature radius R(y) of at least three surfaces of the entrance surfaces and the exit surfaces is represented by Equation (10) when a surface shape in the main scanning direction at the position of the optical axis in the sub-scanning direction is indicated by Z(y) represented by Equation (8), and a curvature in an X direction, that is, in the sub-scanning direction, is indicated by CUX(y) represented by Equation (9), where CX0 is an integer, and CX1, CX2, CX3, CX4, CX5, CX6, CX7, CX8, CX9, and CX10 are respectively a first order coefficient to a tenth order coefficient
z
(
y
)
=
CUY
·
y
2
1
+
1
-
(
k
+
1
)
CUY
2
·
y
2
+
A
y
4
+
B
y
6
+
C
y
8
+
D
y
10
(
8
)
CUX
(
y
)
=
CX
0
+
CX
1
·
y
+
CX
2
·
y
2
+
CX
3
·
y
3
+
CX
4
·
y
4
+
CX
5
·
y
5
+
CX
6
·
y
6
+
CX
7
·
y
7
+
CX
8
·
y
8
+
CX
9
·
y
9
+
CX
10
·
y
10
(
9
)
R
(
y
)
=
z
(
y
)
-
1
CUX
(
y
)
.
(
10
)
2. The optical scanning device according to claim 1 , wherein, when incidence angles of light beams emitted from two of the light emitting parts located at outermost positions in the sub-scanning direction to the reflection surface are respectively indicated by θp in 1[rad] and θp in 2[rad], |θp in 1−θp in 2|>0, incidence angles of the light beams emitted from the two light emitting parts located at the outermost positions in the sub-scanning direction to the surface to be scanned are respectively indicated by θo1[rad] and θo2[rad], and a resolution in the surface to be scanned is indicated by D[dpi], an incidence angle difference Δθo[rad] of the plurality of light beams in the sub-scanning direction which is a difference between the incidence angle θo1 and the incidence angle θo2 satisfies Equation (6)
Δ
θ
o
<
tan
-
1
(
25.4
D
·
1
4
)
.
(
6
)
3. The optical scanning device according to claim 2 , wherein Equation (6) is satisfied in an incidence range of light to the surface to be scanned in the main scanning direction.
4. An image forming apparatus comprising:
a photoconductor that is the surface to be scanned of which an outer circumferential surface is charged;
the optical scanning device according to claim 2 that scans light beams on the outer circumferential surface of the photoconductor; and
an image forming portion that develops a latent image on the photoconductor formed by the light beams from the optical scanning device with a developer, and transfers a developed image to a recording medium so as to form an image.
5. An image forming apparatus comprising:
a photoconductor that is the surface to be scanned of which an outer circumferential surface is charged;
the optical scanning device according to claim 1 that scans light beams on the outer circumferential surface of the photoconductor; and
an image forming portion that develops a latent image on the photoconductor formed by the light beams from the optical scanning device with a developer, and transfers a developed image to a recording medium so as to form an image.Join the waitlist — get patent alerts
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